[TUHS] PL/I stuff - was: Book Recommendation

Alan Glasser alanglasser at gmail.com
Sat Nov 27 12:43:10 AEST 2021

On second thought, given that the Worldnet outage was late 1996, it was most likely that the backups were to 8mm tape. Exabyte?!

 - Alan

> On Nov 26, 2021, at 8:10 PM, Charles H. Sauer <sauer at technologists.com> wrote:
> I haven't done anything with 9 track tapes for a long time, but I used to help my father with his statistical research, processing what at the time seemed massive census and similar data sets on 9 track tape (using PL/I on 370s at U. MO Columbia). Some of his tapes were quite old, stored in his basement and then his garage, but I don't recall problems reading any of them.
> IMNSHO, it all depends on the brand/formulation of the tape. I've been going through old audio tapes and digitizing them (https://notes.technologists.com/notes/2021/08/21/making-private-1960s-and-70s-recordings-public/). Some are over 50 years old and still seem as good to me as when they were recorded. Others, I can anticipate from the brand/formulation that they are going to be trouble, if salvageable at all. Most surprisingly, unbranded and similar budget tapes have survived as well or better than some of the high-priced stuff. A few days ago I tried a reel from 1968. I was dismayed by how many times it had been spliced, but replace the splicing tape and found it viable.
> I have dozens of DDS-2, 3 & 4 cartridges from the 90s that I occasionally try to read. I don't recall any of them failing.
> (We probably should be COFFing this up.)
> Charlie
>> On 11/26/2021 6:30 PM, Larry McVoy wrote:
>>> On Fri, Nov 26, 2021 at 07:23:07PM -0500, Dennis Boone wrote:
>>>  > In my experience 9 track tapes were not guaranteed to be readable after
>>>  > some interval.  In fact, a standard operations procedure was to copy
>>>  > important tapes to new media periodically.
>>> There are always ways in which your backups can go wrong and not be
>>> readable, and I'm not arguing that here.
>>> But 9 track tapes have turned out to be pretty spectacularly long-lived.
>>> I've personally read tapes that were stored for 30+ years in
>>> unconditioned spaces.
>> Contrast that with the write only exabyte tapes.  I lost some stuff to those.
> -- 
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